Method and apparatus for producing crimped staple fibers



April 1, 4 I FQW. KOSTER arm. 8,

IE'I'HOD AND APPARATUS FOR PRODUCING CHI-PHD STAPLE FIBERS Filed Aug. 13, 1941 FREDERICK WL'LMM Ktrsrm BY ALEXANDER BVRLEANEI? Patented Apr. 1, 1947 METHOD AND APPARATUS FOR PRODUCING CRHVIPED STAPLE FIBERS Frederick William Roster and Alexander Bruenner, Meadvllle, Pa., assignors to American Viscose Corporation, Wilmington, Del., a corporation of Delaware 1 Application August 13, 1941, Serial N0. 406,706 7 6 Claims.

independent of any differences of crimping of the individual fibers.

A further object of the invention is to provide a novel apparatus adapted to carry out the method in a commercially practical way. Further objects of the invention will appear from the drawing and the description thereof which follows.

In the drawing, illustrative of the invention,

Figure 1 is an elevational view of the apparatus in cross-section taken on lines I-I of Figure 2,

Figure 2. is a sectional view taken on lines II-II of Figure 1,

Figure 3 is a cross-section taken on lines III' III of Figure l.

Essentially, the method of the invention comprises the feeding of a bundle of relatively untwisted filaments into a cutting device and ap- 25 plying a crimping agent to the filament bundle upon the discharge side of the cutting device. By the expression crimping agent is meant any substance or medium the immediate application of which effects a crimped or curly state in the cut filaments or staple fibers, theexpres'sion being applied hereinafter only to the substance or medium which brings out substantially directly and immediately the crimped condition even though it may be necessary in certain cases for the so-called crimping agent to function in cooperation or in combination with some other ingredient or agent incorporated in or coated upon I the filaments prior to the application of the socalled crimping agent. Similarly, the expression crimping agent is employed regardless of the particular mechanism involved in producing the crimped condition, whether it be the irreguglar' expansion or shrinkage of the fibers, the irregular evaporation orother form of removal of certain ingredients in the filaments, etc. In the simplest embodiment, a heated fluid medium, preferably steam or hot air, acts as an effective crimping agent for cellulose acetate filaments. The invention is applicable to other artificial filaments of different constitution, such as regenerated cellulose from cuprammonium cellulose or from viscose solutions, other cellulose esters and cellulose ethers, filaments of casein, of polyvinyl resins, such as chlorinated and unchlorinated polyvinyl chloride or chlorinated or unchlorinated co-polymers of vinyl chloride and vinyl, acetate. Steam or hot air or mixtures thereof may be employed as the crimping agent for any of these filaments of different constitutions, but other crimping agents may be selected for use with any of these filaments, the agent selected depending upon its adaptability and suitability with respect to the particular nature of the filaments.

In accordance with the method of this invention, care is taken to prevent the crimping agent from exerting any substantial crimping efiect upon any portion of the filament bundle until it is being cut therefrom thereby preventing the cutting of unequal lengths of staple fiber. In this way, the crimping agent acts upon the fibers substantially at the time of their severance whereby the crimping effect is enhanced by virtue of any irregularities or stresses imparted to the fiber structure at the time of cutting and before such irregularities or stresses are permitted to undergo any equalization or compensation that might occur during subsequent treatment processes. Furthermore, by applying the crimping agent simultaneously or practically simultaneously with the cutting of the staple fibers, there is a strong tendency to separate the fiber bundies into individual filamentary fibers and therefore the amount of working necessary to be applied to the fibers in order to open them properly is greatly reduced and in many cases may be entirely eliminated. The application of the crimpingagent to the fibers as they are being severed from the main filament bundle appears therefore not only to effect crimping of the fibers but also to open them up. In some cases, the crimping agent may also serve to assist the feeding of the filaments into the cutting means as will be more particularly described hereinafter with reference to the particular apparatus shown in the drawing.

The condition of filaments as they are fed to the cutter is not a critical matter. For example, they may be in a completely dry and finished state of manufacture or they may still contain some of the solvent with which they were spun. For example, cellulose acetate filaments may still contain a small proportion of acetone or other solvent at the time they are fed to the cutters and the rapid evaporation of such solvent from the filaments effected by the hot air or steam accentuates the crimping .efiects obtainable thereby. The filaments of other constitution may also contain a small amount of their respective solvents at the time they are fed to the cutting device and in the case of viscose, it may be fed 2 to the cutters while in a condition of incomplete regeneration. If desired, special ingredients common in the art may be added to the spinning bath so that these ingredients are contained in the filaments that are spun therefrom and enhance or assist the crimping effect subsequently obtained at the time of application of the crimping agent. Theseknown ingredients just referred I to (not to be confused with the term crimping agent" as used in this specification) are commonly called crimping agents in th art though they exert their crimping effect at a late stage in the formation of the spun filament and frequently only with the cooperation of a second specific agent (this latter agent falling in the definition of crimping agent herein). When such ingredients are employed in this process,. it is preferred to feed the filaments to the cutter before these agents or ingredients have exerted any sage away from the cutting and crimping device,

or they may be treated in accordance with any customary or desired process adapting them to any particular use. i

The drawing shows one form of apparatus particularly suitable for carrying out the method of the invention. The apparatus disclosed 'in the drawing comprises a. feeding disc 2 for feeding filaments to the cutting knife 3 and disc 4. The disc 2 'isprovided with a funnel-like filament entrance 5 which is connected with a radial discharge opening 6. The disc 2 is also provided with a shaft I by which it is adapted to be rotated by a suitable motor not shown. The disc 2 is enclosed in casing 8 which is provided with a cover plate 9 and which is formed integrally with a channel I0 extending tangentially of the annular spacing between the casing and the disc 2 there-' in. The casing is provided with openings 1 l and [2 which permit the cutting knife 3 and disc 4 to ertend into cutting relationship adjacent the periphery of the disc 2. The channel I0 is also provided at its top with a nozzle [3 into which the crimping agent, such as steam or hot air, may be directed by the pipe l4. A discharge duct I5 is attached to the open lower end of the channel l0.

The cutting knife and disc 4 are mounted to be driven by intermeshing gears 16 and I1 whicharedriven by a motor (not shown) through the gear 18. The disc 4, which acts as an anvil, may be an idler, in which case, gear I1 is omitted. Disc 4 may be substituted by a knife, if desired.

In operation of the apparatus, the filament or filament bundle is fed (with or without the assist= ance of an air jet) into the funnel mouth 5 of the disc 2 and passes through its radial channel a by virtue of the centrifugal force developed by rotation of the disc and is directed into the nip of the cutting blade 3 and disc 4 once every reolution of the disc. The crimping agent, suit- 4 amount of the crimping agent from coming into contact with the filaments on the feeding side of the knife 3 and disc 4 so that the fibers cut therefrom have a substantially unvarying length which depends upon the speed of rotation of the disc 2 and'the rate of feed of the filament bundle to the disc. Whil the arrangement of the nozzle I3, knife 3 and disc 4 is preferably as shown, it

is not essential thatthe crimping agent be entirely excluded from contact with the filament bundle entering the bite of the knife 3 and disc (provided the radial velocity 'of the filament bundle is sufficiently rapid so that th agent has insumcient time to effect crimping before c\1 t' 'ting or the centrifugal force upon the filaments holds them under sufiicient tension to prevent any substantial manifestation of the crimping effect prior to'cutting. The radial distance from the peripheral surface of the disc 2 to the interior of its casing may be varied and designed to ac-v commodate any desired length of fiber to be produced. In addition the casing may have the general form of a spiral, in which the crosssectional area surrounding the disc 2 increases in the direction of rotation of the disc to a maxi-' mum at the approach of the bite of knife 3 and a disc 4.

" There may be employed other arrangements of the nozzle for supplying the crimping agent in any desired direction to the staple fibers as they are out. However, the arrangement of the nozzle in the embodiment shown in the drawing is -such that the passage of the crimping agent 'at high velocity transversely of the staple fiber portion of the filament bundle and substantially tangentially of the disc 2 in the direction of its rotation creates a certain amount of reduced pressure in the upper portion of the annular space surrounding the disc 2 and in this fashion re-- 4.0 duces the air resistance encountered by the fila ably steam under a pressure of 30 to 40 lbs. per

square inch, is continuously blown through the nozzle I3transversely of the filaments as they are being severed, directing the severed and crimped fibers through the passage Ill into the discharge duct or pipe l5. It will be seen from the drawing that in this arrangement the knife -3 and disc 4 act as a barrier to prevent any substantial ments protruding from the conduit 6 as they approach the knife 3 and disc 4. This action tends to assist the directing of the filaments into the bite of the knife 3 and disc 4 and to overcome any tendency to drag by virtue of air resistance. Besides effecting crimping of the fibers, the blast of steam. tends to open up any clumps of fibers.

If desired, the jet of crimping agent may be intermittently applied at the instants of cutting successive bunches of fibers from the filament bundle. Instead of a single jet, a plurality of spaced jets may be substituted and they may be made to discharge parallel streams or crossed streams of crimping agent. By adjusting the point of intercrossing of two or more such' streams with respect to the position of the fiber bundle as it is being severed and by adjusting the strength of the several streams of crimping agent, any desired degree of turbulence or, indeed, freedom from turbulence, may be obtained within the channel l0, thereby enabling the operator to obtain the desired extent of opening feeding of said filaments radially outwardly from said axis, periodically cutting the outermost portion of said filaments at a position some distance from said axis, and directing a heated fluid crimping agent transversely of said filaments at their cutting position and tangentially in the same direction as the direction of rotation of said end portion whereby said fiuid tends to reduce the air resistance against said end portion as it approaches said cutting position.

' 2. An apparatus for producing crimped staple fibers from filaments comprising a disc having an axial bore interconnected with a radial bore, means for rotating said disc, cutting means adjacent the periphery of said disc, a channel on the other side of said cutting means substantially tangential of said disc, and means for supplying said channel with a fluid crimping agent.

an axial bore interconnected with a radial bore,

means for rotating saiddisc, a casing surrounding said disc, a space between said disc and casing, said casing comprising a substantially tangentially extending channel, cutting means adjacent the periphery of said disc nearest said channel, and a nozzle in said channel directing a stream of fiuid longitudinally therethrough.

5. An apparatus forproducing crimped staplefibers from filaments comprising adisc having an a 6 axial bore interconnected with'a radial bore, means for rotating said disc, a casing surrounding said disc, a space between said disc and casing said casing comprising a substantially tangentially extending channel, cutting means adjacent the periphery of said disc nearest said channel, and a nozzle in said channel directin a. stream of fluid longitudinally through said channel, a discharge opening in said channel opposite said nozzle and means for supplying said nozzle with steam.

6. An apparatus for producing crimped staple I fibers from filaments comprising a disc having an axial bore interconnected with a radial bore, means for rotating said disk, cutting means adjacent the periphery of said disk, a channel on g the other side of said cutting means, and means fibers from filaments comprising a disc having 4 for supplying said channel with a fluid crimping agent.

EREDERICK WILLIAM KOSTER.

ALEXANDER BRUENNER.

REFERENCES cI'rEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,249,809 Dickie et al July 22, 1941 1,969,770 Taylor Aug. 14, 1934 2,100,588 Claus Nov. 30, 1937 2,173,789 Nickles et al. Sept. 19, 1939 2,228,995 Maxton Jan. 14, 1941 FOREIGN PATENTS Number Country Date German" Aug. 4, 1931 

